+Personal Preventive Methods.--Continence.+[15]--There remains to be considered what is often called the personal prophylaxis of syphilis, meaning thereby the methods by which the individual himself can diminish or escape the risk of infection. The first and most effective method of avoiding syphilis is abstinence from sexual relations and intimacies except in normal marriage with a healthy person. Although it has been alluded to under the moral prophylaxis of syphilis, it deserves to be reemphasized. No consideration as to the justice or desirability of continence and self-restraint can add anything to the simple fact that it is _the_ way to avoid disease, and can be unhesitatingly recommended as the standard for personal prophylaxis. In the experience of physicians it is an axiom that disillusionment sooner or later overtakes those who think they are exempt from this rule. Persons who discard continence in favor of what they believe to be some absolutely safe indulgence are so almost invariably deceived that the exceptions are not worth considering. Although infection with syphilis is no necessary evidence of unclean living, clean living will always remain the best method of avoiding syphilis. [15] The American Social Hygiene Association, 105 W. 40th Street, New York City, can supply pamphlets and lists of authoritative publications bearing on this and related subjects. +The Metchnikoff Prophylaxis.+--The second method of personal prophylaxis of syphilis was developed as a result of the discovery of Metchnikoff and Roux in 1906, that a specially prepared ointment containing a mercurial salt, if rubbed into the place on which the germs were deposited within a few hours (not exceeding eighteen hours, and the sooner the better) after exposure to the risk of syphilis, would prevent the disease by killing the germs before they could gain a foothold. This method of protection against syphilis has been subjected to rigid tests, with fairly satisfactory results. It has been adopted by the army and navy of practically every country in the world, and, as carried out under the direction of physicians and with military control of the patient, has apparently reduced the amount of syphilitic infection acquired in the armies and navies using it to a remarkable degree. The method, of course, cannot assume to be infallible, but if intelligently applied, it is one of the important weapons for the extinction of syphilis in our hands at the present day. It fails to meet expectations precisely in those circumstances and among those persons in whom intelligent employment of it cannot be expected. This of course covers a considerable number of those who acquire syphilis. What disposal an awakened opinion will make of this knowledge remains to be seen. At the present time it may well be doubted whether the indiscriminate placing of it in the hands of anybody and everybody would not work as much harm as good through ignorant and unintelligent use.